The primary issue in this interlocutory appeal is whether the Tennessee health care liability statute of repose, Tenn. Code Ann. § 29-26-116(a)(3) (2012) (“the statute of repose”), is an affirmative defense under Tenn. R. Civ. P. 8.03, that is waived if not raised in a timely manner. Sandra Y. Jones Pratcher died following complications that arose on December 4, 1999, when she received anesthesia before undergoing a cesarean section. On December 1, 2000, her husband, Eddie C. Pratcher, Jr., (“Plaintiff”) filed suit against various health care providers, including Consultants in Anesthesia, Inc. (“Defendant”) and one of its nurse anesthetists. Plaintiff alleged that Defendant, which contracted with the hospital to provide anesthesia services to its obstetric patients, was vicariously liable for the negligent acts of its nurse anesthetist. Plaintiff amended his complaint on March 3, 2006, to assert that Defendant was also vicariously liable for the negligent actions of its corporate owner and president, Dr. Chauhan, who was on call on December 4, 1999, but failed to come to the hospital to administer anesthesia to Plaintiff’s wife. Plaintiff amended his complaint two more times and each time asserted that Defendant was vicariously liable for the negligent acts of Dr. Chauhan. Defendant did not raise the statute of repose as a defense to the vicarious liability claim based on Dr. Chauhan’s alleged negligence. After the jury returned a verdict for all defendants, the trial court set aside the verdict based on an error in the verdict form and its disapproval of the verdict as thirteenth juror. After the trial court granted a new trial as to all parties, Defendant moved to dismiss the case based on the statute of repose and to amend its answer to assert a statute of repose defense. The trial court ruled that Defendant had waived the statute of repose defense and denied the motions. We hold that (1) the running of the statute of repose does not deprive the trial court of subject matter jurisdiction; and (2) as Rule 8.03 explicitly states, the statute of repose is an affirmative defense. Defendant failed to timely raise the statute of repose as an affirmative defense. Therefore, the trial court did not abuse its discretion by denying Defendant’s posttrial motion to amend its answer to assert the statute of repose as a defense. The judgment of the trial court is affirmed.